美洛西林钠的合成

美洛西林钠是一种新型半合成青霉素。在以往的文献中其合成过程中都要使用剧毒品光气作为反应物。今以2-咪唑烷酮为起始原料，经甲磺酰化、酰化等四步反应，合成了酰脲类青霉素美洛西林钠。在合成过程中用氯甲酸三氯甲酯替代光气对其重要中间体l-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的合成工艺进行了改进，不仅避免了使用光气，而且收率也从文献值70％提高到75％。     

注射用美洛西林钠溶析结晶工艺研究

美洛西林钠是一种β-内酰胺酶抑制剂,存在不可逆的特点。许多菌株均具备很好抗菌作用,包括:大肠埃希菌、变形菌属、肺炎克雷伯菌以及链球菌属等。对于美洛西林钠来说,能够发挥显著的抗感染效果,在下呼吸道感染、皮肤感染以及泌尿系统感染等疾病中能够起到显著效果。重点研究了注射用美洛西林钠熔析结晶工艺,希望为美洛西林钠临床应用价值的提升提供有效建议。     

微量量热法研究大肠杆菌对柴胡皂甙和美洛西林钠的耐药性

用瑞典产2277型热活性检测仪测定了不同浓度的柴胡皂甙和美洛西林钠对大肠杆菌的代谢作用,并处理得出最小抑菌浓度(MIC),在小于最小抑菌浓度的药物浓度下培养耐药菌,然后测出在该浓度作用下的耐药菌的热功率时间曲线并处理得出细菌对柴胡皂甙和美洛西林钠耐药性的规律。研究发现细菌对这两种药都产生了耐药性,细菌对美洛西林钠容易产生耐药性且产生的较快,而对柴胡皂甙不易产生耐药性。     

创新工艺

1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的化学合成方法浙江工业大学的研究人员研究了1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的化学合成方法：以有机碱为捕酸剂，以双（三氯甲基）碳酸酯和1-甲磺酰基-2-咪唑烷酮为原料在有机溶剂中反应制得。该产品是新型半合成抗菌素——美洛西林的重要中间体。     

开发导向

Ｄ -对羟基苯甘氨酸开发前景良好Ｄ -对羟基苯甘氨酸是一种重要的医药精细化学品 ,是合成 β-内酰胺类半合成抗菌素的侧链 ,用于生产羟氨苄青霉素（俗称阿莫西林）、头孢克罗、头孢立新、头孢拉定等抗菌素药物。Ｄ -对羟基苯甘氨酸是由ＤＬ -对羟基苯甘氨酸经过生物或化学方法拆分得到的 ,目前的拆分方法有播种法和生物酶法。ＤＬ -对羟基苯甘氨酸的合成方法有苯甲醛法和乙醛酸法。乙醛酸法将成为生产ＤＬ -对羟基苯甘氨酸的主要方法。国内从８０年代开始研制生产Ｄ -对羟基苯甘氨酸 ,目前 ,尚未形成大规模的工业化生产。上海徐杭化工厂、浙…     

美多心安的合成进展

美多心安是一种在治疗高血压、心绞痛等心血管疾病方面具有很好疗效的化学合成药物。本文对其各种合成方法进行了介绍和评价。     

液相色谱-串联质谱法测定化妆品中9种禁用青霉素类抗生素

为建立液相色谱-串联质谱法测定化妆品中9种禁用青霉素类抗生素(包括阿莫西林、氨苄西林、哌拉西林、青霉素G、青霉素V、苯唑西林、氯唑西林、萘夫西林和双氯西林)的方法,将样品经质量分数0.6%氨水乙腈溶液提取、去除有机溶剂后定容,以质量分数0.1%乙酸水溶液-0.1%乙酸乙腈溶液梯度洗脱后,经C18色谱柱(150 mm×2.1 mm×3.5μm)分离后,采用MRM模式进行定性定量分析。结果表明:9种青霉素类抗生素在10～250μg/L的质量浓度范围内线性关系良好,方法回收率在83.1%～110.5%之间,RSD≤7.10%,各组分检出限为10μg/kg,最低定量限为30μg/kg。该方法灵敏度高,重复性好,为化妆品中9种禁用青霉素类抗生素的测定提供了技术手段参考。     

青霉素酰化酶的生产与应用新进展

介绍了青霉素酰化酶的生产及应用新进展。着重介绍了青霉素酰化酶固定化技术的发展。青霉素酰化酶主要应用于6氨基青霉烷酸的工业生产和半合成的β内酰胺抗生素的合成,是在半合成抗生素的生产上有重要作用的一种酶。此外,青霉素酰化酶也可应用于其它的生物转化,如肽的合成、手性化合物的外消旋混合物的拆分。     

7-ADCA、7-ACA、6-APA三大抗生素母核市场分析

7-氨基头孢烷酸(简称7-ACA)、7-氨基-3-去乙酰氧基头孢烷酸(简称7-ADCA)、主要作为头孢类抗生素母核，6-氨基青霉烷酸(简称6-APA)主要作为青霉素类抗生素母核。7-ADCA是合成的头孢羟氨苄头孢拉定、羟氨苄头孢菌素、头孢克罗、头孢他美酯等药物的中间体，都是在国内外市场用量比较大的抗生素药物。由于它们的疗效确切，消费量越来越大，是目前国内外较紧俏药物。7-ACA是制备头孢菌素的关键性中间体，已成为当今国际抗生素市场的主角。医药行家指出，若无7-ACA原料，所有头孢菌素生产必将成为“无米之炊”。几乎所有的半合成青霉素的制备都依托青霉素母核6-APA为基本合成原料。青霉素是世界上使用最广泛的抗生素之一，但因大量耐药菌的出现，目前世界各国普遍使用半合成青霉素来解决青霉素药效大降的问题，以达到更好的药效。据估计，目前7-ACA全球总需求量约2500t，而中国市场就占有1200t。在世界范围内目前对6-APA的需求量约为25800t，到2005年将达到32800t；对7-ADCA的需求约为6000t，到2005年将达到7000t。     

全国感光材料标准化技术委员会 2012年度标准化工作会议暨国行标审查会在济南圆满举行

<正>2012年12月4日-5日,全国感光材料标准化技术委员会(简称感标委)2012年度标准化工作会议暨国行标审查会在济南顺利召开。来自中国乐凯胶片集团公司、中国科学院理化技术研究所、北京化工厂、中国电影集团洗印分公司、上海电影技术厂有限公司、罗赛洛(广东)明胶有限公司、天津美迪亚影像材料有限公司、上海交通大学、常州市     

Effects of flue gas desulphurization sludge on the pozzolanic reaction of reject-fly-ash-blended cement pastes

Reject fly ash (rFA), a coarse portion of the pulverized fuel ash (PFA) produced from coal-fired power plants and rejected from the ash classifying process, has remained unused due to its high carbon content and large particle size (>45 μm). However, the reject ash may have potential uses in chemical stabilization/solidification (S/S) processes that require relatively low strength and low chemical reactivity. Flue gas desulphurization (FGD) sludge is a by-product of the air pollution control process in coal-fired power plants. Its chemical composition is mainly gypsum. As there is no effective usage of both of these materials, it was of interest to conduct research on the possible activation of rFA using FGD. This paper presents experimental results of the effect of FGD on the pozzolanic reaction of rFA-blended cement pastes with or without Ca(OH)₂ and chemical activators. The results show that FGD take effect as an activator only at late curing ages. Adding Ca(OH)₂ activates the hydration of rFA. Chemical activator, such as alkali sulphate, is more effective in enhancing the strength development and degree of hydration of rFA than CaCl₂ in the rFA-Ca(OH)₂-cement system. But CaCl₂ is more effective in the rFA-Ca(OH)₂-FGD-cement system. The chemical activators speed up the reaction of the rFA through the formation new hydration products and elevating the pH value.     

化学后处理法降低TDI-TMP固化剂中游离TDI的研究

介绍了以一种化学后处理法降低TDI-TMP型聚氨酯固化剂中游离TDI的工艺方法,其合成思路主要为：利用反应过程中空间位阻的影响而导致在TDI单体及聚氨酯加成物上-NCO基的化学反应活性的差异,选用高选择性的催化剂和特定的工艺条件,促进游离TDI的自聚反应,并使其成为聚氨酯固化剂中的组成部分,从而达到降低游离TDI之目的。     

Structure characterization of films from drying oils cured under infrared light

Drying oils have been considered as water resistant coatings for bio‐based packaging materials; however, their curing rates are slow for industrial applications. Infrared radiation was investigated in this study as a means to increase the curing rate of linseed and tung oils. The effect of oil pretreatment with gamma radiation was also investigated. FTIR spectroscopy was used to monitor chemical changes during oil oxidation. Results indicated that infrared radiation increased the curing rate of linseed and tung oils. The oxidation rate of both oils, as monitored by the decrease of the 3010 cm^?1 FTIR peak, followed an exponential decay. The structure of cured films was examined by SEM. Images of films cross section were used to develop a qualitative model of the curing process. Linseed and tung oil showed differences in structural development during drying. In the case of linseed oil, the formation of a tough skin layer slowed down oxygen diffusion to the oil underneath, resulting in slow curing. For the case of tung oil, the skin layer shrank as it formed allowing oxygen diffusion and fast curing of tung oil. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of nucleation seeding on the hydration kinetics and compressive strength of alkali activated slag paste

Addition of pure calcium silicate hydrate (C–S–H) to alkali-activated slag (AAS) paste resulted in an earlier and larger hydration rate peak measured with isothermal calorimetry and a much higher compressive strength after 1 d of curing. This is attributed to a nucleation seeding effect, as was previously established for Portland cement and tricalcium silicate pastes. The acceleration of AAS hydration by seeding indicates that the early hydration rate is controlled by nucleation and growth. For the experiments reported here, the effect of C–S–H seed on the strength development of AAS paste between 1 d and 14 d of curing depended strongly on the curing method. With sealed curing the strength continued to increase, but with underwater curing the strength decreased due to cracking. This cracking is attributed to differential stresses arising from chemical and autogenous shrinkage. Similar experiments were also performed on Portland cement paste.     

Chemistry of epoxide resins. XVII. Influence of structure and curing conditions on the density,degree of cure,and glass transition temperature during the curing of epoxide resins

During an investigation of various epoxide resin systems, some cases were found in which the room temperature density decreased with increasing curing temperature and increasing degree of cure. In other systems the density was found to be independent of the curing temperature. In these cases it is possible by deliberately stopping the reaction to measure density values which also decrease as the curing progresses. This unexpected behavior can be explained in a purely physical manner from the pattern of the density changes during an entire curing cycle. The density decrease of the noncured mixture, which is due to the increased curing temperature, outweighs all contraction effects consisting of isothermal chemical and cooling shrinkage, whereby the latter is dependent to a great extent on the glass temperature. In those cases where the glass temperature exceeds the curing temperature, the chemical reactions come to a standstill, when the temperature difference reaches a certain value, i.e. it “freezes chemically”. By means of values that can be measured readily at low temperatures, it is possible to construct diagrams from which the variation of the density at higher temperatures of the curing cycle can be estimated.     

化学处理方法对剑麻纤维/环氧树脂固化反应动力学的影响

通过采用非等温DSC方法．研究了不同化学处理方法对剑麻纤维/环氧树脂固化体系的固化反应动力学的影响,计算了固化反应的活化能,为共混体系的固化反应机理的研究提供了依据。     

反应型环氧树脂固化剂的研究现状与发展趋势

环氧树脂是应用广泛的热塑性高分子预聚物,只有加入固化剂后方能显示出优异的性能,因此固化剂对于环氧树脂的应用及对固化产物的性能发挥着巨大的作用。在环氧树脂固化剂中,又以反应型固化剂的固化效果比较优异且使用方便,品种众多。综述了反应型环氧树脂的固化剂的种类及反应机理,介绍了近年来国内外几种性能优异的反应型环氧树脂固化剂,其中包括多元胺类固化剂、酸酐类固化剂、多元硫醇类固化剂、咪唑类固化剂等,指出其发展趋势是环保型、耐高温、高强度、高耐久性及快速固化。     

Cure kinetics of bismaleimides as basis for polyimide-like inks for PolyJet™-3D-printing

Since polyimides are well known for their excellent chemical and thermal stability and outstanding mechanical properties there is increasing interest in developing polyimide-based inks to produce additively manufactured parts with properties superior to those of currently available materials. Usage of bismaleimides (BMI) as precursors allows polyimides to be fabricated via PolyJet™ printing (Stratasys Ltd., Rehovot, Israel). Characterization of the curing kinetics is a central part of process development, as fast curing initiated by UV light is desired. Here, a comprehensive study of thermal and UV curing of BMI oligomers with various molecular weights and chemical structures is presented. Fourier transform infrared spectroscopy serves as a tool for determining the curing degree. Furthermore, an estimation of the activation energy for thermal curing is performed. UV curing of the selected BMIs leads to highly crosslinked, thermoset polymers with excellent chemical resistance and thermal stability which are of great interest for PolyJet™ 3D printing. © 2018 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47244.     

Generation of environmentally enhanced products: Clean technology for paper chemicals

The modification of existing chemical manufacturing processes to selectively remove unwanted chemicals in products, offers a realistic approach to novel clean technologies. Adjunct biotechnological processing offers a means to achieve the manufacture of new environmentally enhanced products (EEPs). This paper describes the development and implementation of a bioprocess for the manufacture of an enhanced paper chemical. The process was integrated into existing manufacturing plants involved in the production of neutral curing poly(aminoamide) chemicals which are used commercially to impart wet-strength to paper products such as tissues and towels (e.g. Kymene^™ wet-strength resins). A consequence of the epichlorohydrin chemistry involved in the polymer's manufacture, haloalcohols (predominantly, 1,3-dichloropropan-2-ol (DCP) and 1-chloropropanediol (3-CPD)) contaminate the product. The objective was to reduce the concentration of the two haloalcohols in Kymene^™-SLX wet-strength resins (c. 8000 ppm db) without affecting the performance of the product. A two-membered bacterial consortium was used in an aerobic stirred tank bioreactor system which was capable of rapidly reducing the concentrations of DCP and CPD in an aqueous solution of the wet-strength resin to less than 1 ppm and 5 ppm respectively. A 3000 dm³ bioreactor was integrated into two established manufacturing plants, generating a reliable and predictable process to enhance the value of the neutral curing wet-strength chemical. ©1997 SCI     

粉煤灰掺量对海水海砂高性能混凝土性能的影响

通过宏观力学性能、化学收缩、pH值、氯离子浓度等测试和SEM、XRD等微观表征研究粉煤灰掺量对海水海砂高性能混凝土性能的影响。结果表明:为维系钢筋钝化膜稳定,高温蒸养时粉煤灰掺量不宜大于30%(质量分数,下同),标养时粉煤灰掺量不宜大于50%;海水海砂高性能混凝土中游离Cl^-浓度随养护时间波动,前期先升高后骤降,后期缓慢增加,标养条件下Cl^-浓度明显低于高温蒸养条件下;海水海砂高性能混凝土具有早强性,其强度随粉煤灰掺量增加大致呈下降趋势,高温蒸养可明显提高混凝土抗折、抗压强度;粉煤灰掺量越多,残留的未水化颗粒越多,高温蒸养可有效改善混凝土微观结构,提高致密性;粉煤灰掺量过多或过少均会增加硅酸盐水泥体系的化学收缩,粉煤灰掺量为30%和40%时混凝土化学收缩值较小。